Heat protection element

ABSTRACT

Fire and heat protective flexible web, comprising a flexible material. The web comprises, in a cross section view from the heat exposed side: 
     a selected first support layer ( 1 ) consisting of a steam permeable, solid and tear resistant textile, 
     one or more fluid transporting layers ( 2 ) consisting of a liquid permeable and airy textile, 
     a selected second support layer ( 1 ) consisting of a steam permeable, solid and tear resistant textile, and 
     a conduit ( 6 ) mounted at least in the upper part of the fire projective web, for supply of fluid to the fluid conducting weblayer, and to disperse the fluid evenly in the longitudinal extent of the web, whereby the different layers are tightly connected surface-to-surface by means of seams, adhesives, point fixing or similar.

The invention relates to a flexible heat and fire protective web of thetype presented in the preamble portion of the attached claim 1.

BACKGROUND

Fire inhibiting structures, in particular fire inhibiting carpets whichcan be laid over existing conventional oil retaining structures areknow. These fire resistant carpets and other fire resistant materialsare often made of ceramic fiber materials or woven materials which canwithstand high temperature. The materials are often combined with metalswhich have good heat conducting properties.

A disadvantage concerning materials which contains metals, is that theyhave a tendency to oxidize/corrode when sea water is present, and theirstructure changes and weakens when heated.

There are exit barriers which contain both solid and air filled flexibleemergency buoy-ancies. Fire restraining barriers containing solidemergency buoyancies can not be coiled in or payed out from a reel. Thismakes handling difficult and demands a lot of extra work, whichconstitutes a danger for the barriers. Barriers with flexible floatingchambers have little freeboard and spare buoyancy, and therefore thereis a chance that they might go down under water during normal tug speed.

The barriers available today are expensive and heavy, and are made up ofmaterials with limited life during a fire, where temperatures in thefire may vary between 800-1300° C. The fire barriers generally have alow buoyancy/weight ratio compared to normal barriers. This causes themto float heavily in the sea, and have poor wave following properties,ans this creates weather-dependent use in open waters. In addition thematerials are rigid, and not very flexible, which results in a worseningof the sea-properties.

OBJECT

The object of the invention is to provide a fire and heat protective webwhich eases or overcomes the disadvantages of known fire protectivedevices and extinguishing methods.

THE INVENTION

The object is accomplished with a flexible heat and fire projective webaccording to the characterising portion of claim 1, and a use of thesame according to claim 6. Further advantageous features are given inthe dependent claims.

The invention relates to a fire and heat protective, usually flexible,web, which is characterised by comprising, in a cross section of the webfrom the heat exposed side:

a selected first support layer consisting of a steam permeable, compactand tear resistant textile web,

one or more liquid conducting layers of a liquid permeable and airytextile material,

a selected second support layer consisting of a steam permeable, compactand tear resistant textile web, and

a conduit mounted at least in the upper part of the fire protective web,for supply of fluid to the fluid conducting weblayer, and to dispersethe fluid evenly in the longiudinal extent of the web, whereby thedifferent layers are tightly connected surface-to-surface by means ofseams, adhesive means, point fixing or similar.

Although the invention in the following description is, for simplicity,described with special reference to use concerning oil barriers at sea,it should be obvious to a person skilled in the art that the fireprotective web can be used for other applications, as will bedemonstrated in the following further detailed description.

The fire and heat protective effect resulting from the web according tothe invention, arises as a result of a combination between active andpassive cooling, in the form of a fluid which flows through the porousand fluid permeable textile material. Before and during use of the webaccording to the invention, water or another nonflammable fluid isadded, through a perforated water tube. Fluids which have boiling pointssimilar to sea water, or are adjusted to the textiles' resistance toheat, can be used.

Temperature control of the web according to the invention, both insideand on it's surfaces, takes place according to the following principle:When a fluid boils, the temperature in the fluid adjusts to it's boilingpoint, and thereby automatically limits the maximal temperature in theweb. The temperature and the evaporation from the surface of the water,stays constant during boiling, and is therefore independent of thetemperature of the fire or source of heat. The maximum temperature inthe wet fire protective web is therefore 100° C., if the fluid used iswater. The minimum amount of water needed to keep the temperature belowthe boiling temperature, is equal to the amount which evaporates fromthe web. By increasing the waterflow, further cooling will be achieved.

The term “fluid permeable and airy textile material”, used about thefluid conducting layer, means any textile material, comprising syntheticand/or natural fibres which shows a high capacity to absorb water and ahigh waterflow capacity, e.g. woven, non-woven and needle cloth of e.g.cotton.

For cloth materials with relatively low inherent strength, e.g.non-woven cloth, it is preferred to combine it with a support layer onone, or preferably both sides. The selected support layer will, inaddition to a protective and supporting function, also serve to keep thecooling fluid which flows in the fluid conducting layer, better in itsplace, and also makes the cooling fluid available to the heat exposedside of the web.

The support layer may comprise materials which correspond to the fluidconducting layer, but it will have a denser structure with higherresistance to tearing, and a lower capacity for flow of fluid. Thesupport layer still shows a capacity to exchange steam between thesurroundings and the fluid conducting layer.

In the simplest embodiment, the web includes, an extended horizontalconduit, e.g. in the form of a perforated and flexible tube, at theupper end of the web, to provide an even supply of cooling fluid alongsubstantially the whole length of the web. In cases where the web isvery large, or very intense heat exchange is expected, it could beconceivable to provide horizontally conduits, generally parallel witheach other, extending downwards in the web, to replace cooling fluidwhich has evaporated at the upper side of the web.

At the least heat exposed side of the web, may be mounted a block layerwith steamblocking and eventually heat leading qualities, e.g. a plasticfilm like PVC, or flexible metal-foils, e.g. aluminium, so thateventually absorbed heat can be spread out if needed. Such a block layerwill prevent eventually evaporation of fluid on the cool side, and alsoprevent draining of cooling fluid from the fluid conducting layer, andin this way, even more cooling fluid available to the heat exposed sideof the web.

A typical thickness of the web according to the invention will be about2-4 mm, which gives a dry weight of about 300-400 g/m² and a wet weightof about 1000-3000 g/m². Thickness, layer construction, andimplementation of conduits will of course have to be adjusted to theintended use, and will vary from very simple constructions for someapplications, to more complicated constructions for larger applications.

The method for mutual fastening of the different web layers in the webaccording to the invention, is not essential, but the different layersshould be surface-to-surface with each other, to make sure that thewhole web gets moistened by the supplied cooling fluid. Consequently,the different web layers can be fastened to each other by e.g. a stableadhesive means, point fixing or by seams. When fastening with seams, theseams must be established generally parallel and vertical consideringthe web's position during use, so that there will be establishedvertical channels supplying the flow and spread of water in an even wayin and over the web according to the invention. Tests have proven thatan advantageous distance between the seams is about 5-10 cm.

The ratio between active and natural flow of water varies according tothe choice of textiles and cloth materials. Tests have proven that a webaccording to the invention with active cooling can receive about 240times more water per time and area, than the amount with natural coolingper time and area. This offers the possibility to cool down towards thetemperature of the cooling water.

To combine water and air cooling, it is possible to mount a distancingmeans inside the web (the least heat exposed side), to allow cooling andcondensation of steam which is localised between the web and theproduct, or the object to be protected.

To sum up, to gain even dispersion of temperature in the web accordingto the invention, both the absorbing and flow through properties of thetextile and the selected block layer's steam blocking and heatconducting properties are utilized. These properties are necessary to

1) compensate for evaporation,

2) reduce evaporation and salt deposit by lowering the temperature ofthe web and surface,

3) protecting products with a lower temperature resistance than 100° C.

4) rinse salt created during evaporation of sea water, and

5) prevent passage and heating of water vapour on the cold side of theweb.

The web according to the invention is particularly suited for use, withor as, oil barriers. The flash point of the oil increases with timeafter spill at sea. Oils with a flash point higher than the surfacetemperature of the web, will not be set on fire or be able to burn onthe surface of the web. Active cooling will reduce the temperature ofthe surface of the web down towards the temperature of the coolingfluid. Active cooling or the extent of active cooling can thereby beregulated to avoid crude oil e.g. burning in the web. If the dry web ismoistened with oil, the oil will partly flow off and at the same timeemulsify in the web, when it is used active cooling. This propertyprotects the web from catching fire, because emulsified oils do not burnuntil the water is evaporated. Steady supply of water will thereforeprevent the emulsion from evaporating.

Since the material has an ability to conduct fluids, the water can besupplied with fire lather for further cooling or improvement of fireprotective properties. The principle can also be used for supply of oilrepellant chemicals. The web material will then function as a chemicalbarrier, holding the oil away from the web surface. Water will flowthrough the material, and the web will function as an oil/waterseparator.

For simpler cleaning; chemicals/soaps can be added to the water.

To protect conventional barriers with a low buoyancy/weight ratio, thecarpet may be equipped with installed longitudinal air filled tubes oneach side of the barrier.

In addition to use as heat shields and fire restrictive protections forbarriers, the web can also be used in other industrial operations. Forexample as fire protection for storage tanks of oil or gas atrefineries, or protection of personnel in residential areas at gas oroil rigs, hotels, housings and vessels. The material and the method canalso be used in textiles and work clothes for protection of fire crewsand for extinguishing of fire engines or fires of limited dimensions.

The invention in the following detailed description will be describedwith reference to the accompanying drawings, where:

FIG. 1 shows an embodiment of a web according to the invention,

FIG. 2 shows an embodiment in which the web is arranged to protect anexisting oil barrier, and

FIG. 3 shows use of the web as an oil barrier.

FIG. 1 shows a perspective view, partly sectioned, of an example of anembodiment of the web according to the invention. The web comprises asupport layer 1 localised against the heat exposed side, a fluidconducting layer 2 brought surface onto surface with the first supportlayer, a second support layer 3 and finally a blocking layer 5.Perforated conduits (6 a, 6 b, 6 c) are located between support layer 1and 3, and provides a water supply to the whole length of the web bymeans of a pump or a fall reservoir.

FIG. 2 shows a sectional view through an exiting oil barrier 11, whichfloats on the sea surface 14. A web 10 according to the invention isplaced around the oil barrier 11, and is, at its lower end equipped withemergency buoyancies 12 a and 12 b. A perforated conduit 6 is located atthe upper end of the web in the drawing, to provide a water supply. Theemergency buoyancies 12 a and 12 b will compensate for the increasingweight, and at the same time give the barrier itself an increasedbuoyancy, thereby improving the buoyancy/weight ratio and the wavefollowing properties. The web according to the invention, can thereby beused with all existing types of barriers, including those which havepreviously too low a buoyancy to be used in open waters.

FIG. 3 shows a web 10 according to the invention, in the shape of aindependent oil barrier with support from emergency buoyancies 12 a and12 b placed at each free longitudinal edge, and ribs 13 of spring steelor similar which shape and keep the web up, even without the use of airfilled or solid emergency buoyancies, which are necessary for normalbarriers.

EXAMPLE 1

Multi Layer Web

Tests with a 0.2 m×0.28 m web incorporating a relatively hard cloth(non-woven) as a fluid-carrier, with a layer of a cotton textile on eachside, have proven that if the web is laid over a propane flame, assumedtemperature of the flame is about 700-750° C., the surface temperatureon the cold side will vary from 9-87° C., and on the hot side thetemperature will be 10-12° C. higher, depending on the temperature ofthe cooling water and the amount of cooling water which flows throughthe web. The prototype has been used for a total of 12 hours burningover the propane flame from a cooker, without getting visible marks orweakening the properties of the material.

Tests with lubricating oil and evaporated crude oil emulsion on theweb's hot side, after being moistened with water, gave no marks orvisible damage to the web after over 1 hour of burning.

Also performed were tests in which the web in a dry condition wasmoistened with lubricating oil, and afterwards supplied with coolingwater, as described earlier. After 2 hours of burning over a propaneflame there was no visible damage or marks on the web.

EXAMPLE 2

One Layer Web.

Tests were also performed on a web comprising only one layer of cottoncloth with thickness 1 mm, and side lengths 22.5×29.5 cm. The flowcapacity of the web was 28 mL water/min. The flow capacity was measuredby placing one edge of the web in a tub with water, and the other endover the tub-edge so that the free end was below the water surface inthe tub. The flow capasity was then determined by measuring the amountof water which flowed out of the free end of the web. The absorptivenessof the web was measured by weighing the web when it was dry, and when itwas fully moistened. The resulting value for this web was 10 kg (dry weband water) per kg dry web.

The web was continuously supplied with cooling water through a conduitalong the upper end of the web, after which a weld flame(propane/oxygen) was directed against it's surface.

Even after 5 min heating it was not possible to observe any visibledamage to the web. Consequently, this shows that the web according tothe invention also exhibits the desired effect even with just one layer.

Accordingly, the invention provides a new heat and fire protective webwith improved properties compared to known fire protecting means: Thespecial properties of the web together with the cooling principle, makesthe temperature in the web independent of the temperature of the heatsource. The water film which forms on the surfaces of the web, preventssoot from settling. Chemicals, water and fire lather can be pumpedthrough the web to ease cleaning and to supply further fire resistanteffect, if desired. Lubricating oil which fixes to the web will berinsed off during use in a fire.

The web material has a low weight when it is not moistened. This leadsto simpler handling and mounting compared to existing fire restrainingcarpet materials which are used. The material is more flexible, bothwhen dry and wet, than other materials which are used, and thereforeaffect the sea properties to a lesser degree.

When the web is supplied with its own emergency buoyancies, the weightincrease during operation is compensated, and in addition the sparebuoyancy will increase the buoyancy of existing conventional barriers.This increases the utilization possibilities for this kind of product.

The web will be cheaper to purchase than existing fire restrainingproducts. This is because the web has longer operational lifetime undera fire, and do not decompose substantially from the temperature of afire. Existing equipment for mechanical collection of oil can be usedfor pumping water.

The web according to the invention can be coiled on a reel, togetherwith the barrier which it shall protect. This greatly reduces theresponse time and simplifies postponement and handling.

The web according to the invention will provide greater flexibility inchoice of existing textiles, because the maximum temperature using seawater as the cooling media, automatically restricts it to about 100° C.This results in a greater freedom for design of the product, and cantherefore easily be adjusted to use in other fields.

The web according to the invention may be used as fire protection inmany applications. The product is environmental friendly and will notrelease any form of poisonous gases, when it is exposed to hightemperatures. It is maintenance-free and does not contain any metalswhich may corrode when it is in touch with water or if any chemicals areused. It has insulation material to further improve the insulationproperty.

To protect special objects from ultraviolet radiation, in combinationwith this web a e.g. aluminium foil may be used. Other materials canalso be used for this purpose. The thickness of the web will typicallyvary between 2-4 mm. This gives a dry weight of <0.5 kg/square metre.The wet weight will vary with the thickness and the textiles' propertiesfor absorbing water, and is normally between 1-3 kg per square metre.

If the web is permanently fixed to existing constructions, no extrainstalled textile strength is needed. To resist unexpected fires, beforethe water cooling is initiated, and to avoid damage to the textiles invulnerable areas, the web can be provided with an outer mechanicalprotection. If the web is used as a mobile fire protection, the strengthcan be varied by choosing armoured textile combinations. The combinationweb can further be equipped with ribs and shaped as a temporary“evacuating tent”. Since the web can be built up solely of textiles, itwill not corrode, and the structure in the web will not weaken underheat-influence, even with temperatures up to 3000° C. For mobile use,the web can easily be handled with it's low weight, and stored and setout in reels.

The web according to the invention has been tested in fires with oil,but the properties of the product have not been affected. If the web ismoistened with oil and the water is switched on afterwards, the oil willbe displaced by the water. Oils with a higher flash point than thesurface temperature of the web, will not be set on fire or bum on thesurface of the web.

The web according to the invention has the following advantages as afire protection equipment:

the boiling point of the water limits the maximum temperature on thesurfaces of the textile,

extended possibility to protect existing constructions with lowresistance to fire,

increased flexibility in choice of building materials demanding fireprotection,

low consumption of water,

it can be connected to an existing sprinkler system,

optimum protection—water is supplied where it is needed,

low weight when it is dry,

low production costs,

independent of temperature and heat radiation,

over time, it resists unlimited temperature and heat radiation,

environmental friendly product,

produces no poisonous gasses during use,

maintenance free and long lifetime,

no corrosion,

flexible basic material—can be coiled on a reel for mobile use,

cheap to purchase,

inbuilt possibility for lather laying.

There exists many areas for use both ashore and at sea where theinvention can be used to increase fire-safety, including the possibilityfor fire extinguishing and improvement of safety for personnel. Some ofthese topical areas are:

oil barriers,

fire walls,

oil rigs,

protection for burning off gases (replaces flare stacks),

residential areas in floating and stationary installations,

escape routes,

control room,

storage tanks for oil, gas and chemicals,

computers and computer centrals,

libraries,

museums,

mobile heat shield for fire extinguishing,

carpet for fire extinguishing,

protection of mobile fire means (cars etc.),

fire suits,

ammunition storages/rooms,

fire cupboards.

What is claimed is:
 1. Fire and heat protective web equipped with meansfor feeding liquid to the web, wherein a cooling-effect is established,the protective web comprising, in a cross section view from the heatexposed side: a selected first support layer (1) consisting of a steampermeable, compact and tear resistant textile material, one or morefluid conducting layers (2) of a liquid permeable and airy textilematerial, a selected second support layer (3) consisting of a steampermeable, compact and tear resistant textile material, and at least oneconduit (6) mounted in fluid communication with at least one fluidconducting layer for supply of fluid to the fluid conducting layer andto disperse the fluid evenly in the longitudinal extent of the web,whereby the different layers are tightly connected surface-to-surface.2. Web according to claim 1, wherein at least one of said support layers(1, 3) comprises a thin and dense textile of absorbing fibres.
 3. Webaccording to claim 2, wherein said thin and dense textile of absorbingfibers is a cotton textile.
 4. Web according to claim 1, wherein theconduit (6) is perforated and generally flexible and integrated in andgenerally arranged along the upper part of the fire protective web,wherein the perforations are evenly distributed along the whole lengthof the conduit, and incorporated into, or in connection with the web. 5.Web according to claim 1, wherein an impermeable foil (5) is placedbetween said one or more fluid conducting layers and said second supportlayer.
 6. Web according to claim 1, wherein a plurality of conduits (6a, 6 b, 6 c) are provided in connection with the web, and they aregenerally parallel to each other.
 7. Web according to claim 1, whereinsaid web further comprises an impermeable thermal insulating foil, whichis fixed surface-to-surface with the unexposed side of the fluidconducting layer.
 8. Web according to claim 1, wherein said web isarranged in an upwardly arched configuration forming an upper part inthe center of the web and wherein said conduit is mounted at least inthe upper part of the fire protective web.
 9. Web according to claim 1,wherein an impermeable foil is attached to the outside surface saidsecond support layer, thereby making the foil the farthest surface fromthe heat exposed surface of the web.
 10. A web which comprises, in across section view from the heat exposed side: a selected first supportlayer (1) consisting of a steam permeable, compact and tear resistanttextile material, one or more fluid conducting layers (2) of a liquidpermeable and airy textile material, a selected second support layer (3)consisting of a steam permeable, compact and tear resistant textilematerial, and at least one conduit (6) in fluid communication with atleast one fluid conducting layer for supply of fluid to the fluidconducting layer and to disperse the fluid evenly in the longitudinalextent of the web, whereby the different layers are tightly connectedsurface-to-surface, as a fire protective web for oil barriers, forcovering storage tanks which stock flammable products, for covering apersonnel room in flammable surroundings, as an element in fireprotective suits, for covering a fire engine, for extinguishing carfires and similar, as a rescue tent, as a cover for a fire wall, and forsimilar fire protection purposes.
 11. A fire and heat protective webequipped with means for feeding liquid to the web, wherein acooling-effect is established, the protective web comprising, in a crosssection view from the heat exposed side: a selected first support layer(1) consisting of a steam permeable, compact and tear resistant textilematerial, one or more fluid conducting layers (2) of a liquid permeableand airy textile material, and at least one conduit (6) mounted in fluidcommunication with at least one fluid conducting layer for supply offluid to the fluid conducting layer and to disperse the fluid evenly inthe longitudinal extent of the web, whereby the different layers aretightly connected surface-to-surface.
 12. Web according to claim 11,wherein said web further comprises an impermeable foil layer attached tothe outside surface of said fluid conducting layer, thereby making thefoil the farthest surface from the heat exposed surface of the web.